In the past, optical films have been bonded together during fabrication of liquid crystal displays and other optical devices. Avionics engineers have routinely endeavored to utilize predetermined portions of previously manufactured optical film sheets because of the preferred nature of the portion in comparison to other portions of the optical film. When multiple optical films are used, in which each film has a predetermined preferred portion, it is often desirable to attempt to align these preferred portions during the process of bonding the optical films together. One approach has been to use a pen or other marker to encircle the preferred portion of each film and then attempt to manually align the encircled portions by a simple visual alignment of one encircling line on a first optical film with another encircling line on a second optical film.
While this approach has benefits of simplicity and ease of use, it also has significant drawbacks. A significant problem of this type of approach is that it often fails to provide sufficient angular alignment of the critical axes of the various films as is often required by the most rigorous performance specifications.
Consequently, there exists a need for improved methods and apparatuses for aligning preferred portions of optical films in a multi-film bonding process.